System Overview

CNG refers to compressed natural gas，which means the low pressure gas is pressurized to 25 MPa and becomes a high-pressure natural gas.

The liquefied natural gas (LNG) is transported to the filling station which is then purified, pressurized and dehydrated. It will then be passed through the sequence control panel and fed into the gas storage system where it is measured and used by external users through the filling machine. 

Process Flow Diagram of the CNG Regulator Station with Gas Storage Device

Major Component

• Natural gas regulator metering system

• Natural gas purification system

• Natural gas compression system

• Natural gas storage system

• CNG filling system

• Control system

Technical Features

• LNG fueling stations will not only fuel LNG vehicles but with the installation of a simple high pressure pump and vaporizer, they can also generate high quality CNG gas in the same station for different applications.

• CNG generated from LNG is called LCNG. Both LNG and LCNG can be delivered at the same single station. 

• A LNG/LCNG fueling station is more flexible than a single functional NG fueling station since it provides service to short fueling range vehicles and also long fueling range LNG vehicles.

• When a natural gas vehicle (NGV) fueling station is planned, it will typically be both a LNG and LCNG combined station and is depicted in the following diagram.

        The Filling Stations of Compressed Natural Gas (CNG) 

Applications

The CNG filling station is primarily used for refilling cars which use the natural gas as fuel. This technology has been successfully applied to the Huoqiu, Anhui LNG filling station and more such stations throughout China.

The Natural Gas Vehicle (NGV) Fueling Station  

Seawater desalination, which is the production of fresh water from saline water, is a water treatment technology used for fresh water resources utilization. Reverse osmosis (RO) desalination is a reliable technology which produces large amount of fresh water with relatively low costs. With the desalination technology, SafBon guarantees the stable supply of potable water and industrial water to municipalities, power, oil & gas, mining, resorts and other industries.

Over the years, SafBon has been active in the field of desalination. Since SafBon has forayed into the desalination business field, the SafBon desalination expertise, experiences and technologies utilized has improved tremendously. SafBon has enhanced desalination capabilities which are very cost efficient. Furthermore, SafBon utilizes membrane desalination technologies with SafBon own dissolved air flotation (DAF) and ceramic flat membrane (CFM) products which provide extremely good protection of the RO installation against organic fouling and scaling.

Pre-treatment Process

To minimize the impact of membrane fouling, which reduces membrane performances and lifetimes, pre-treatment process is required. There are several types of fouling process, including colloidal fouling, inorganic salt scaling and bio-fouling. This is also affected by the plant location, the intake seawater type and the seasonal variations. As a result, the raw water may contain significant amount of suspended solids (SS), colloidal pollution and dissolved organic pollution.

The pre-treatment process SafBon uses includes DAF and traditional coagulation, sedimentation and filtration. The SafBon DAF shows higher removal rate in low density contaminants (density < H₂O, such as plankton, algae and oil) removal than the conventional processes. The CFM application in filtration process, results in following benefits:

• Longer lifetime: 3-5 times longer;

• Higher flux: 2-10 times higher;

• Less chemical consumption: 50% less;

• Less energy consumption: 50% less;

• High recovery rate: up to 98%;

• Less back-wash: once per day, only 120 s needed;

• Higher mechanical strength: easy for cleaning.

RO Desalination Characteristics

• Flexible optional pre-treatment processes available for specific conditions;

• Automated desalination plants;

• Suitable in seawater, brackish water and industrial water treatment;

• Small footprint;

• Facilitates operation and maintenance;

• Minimize energy and chemical consumption;

• Capacity: 1,000 m³/day per unit;

• The produced fresh water meets the requirements of irrigation water, industrial water, even the drinking (WHO standard) water standards;

• Application of the advanced recovery systems to minimize the energy loss.

RO Desalination Advantages

Owing to the rapid development of membrane technology in recent decades, SWRO has been widely applied with its significant advantages:

• Low energy consumption;

• Low chemical consumption;

• High recovery rate of fresh water;

• Low maintenance costs;

• Green financing.

SWFGD Technology

The seawater flue gas desulfurization (SWFGD) process refers to absorption and neutralization of SO₂ in the flue gas by tapping on the natural features of seawater. SafBon SWFGD technology is a reliable and highly-efficient technology with self-owned intellectual property.

The SWFGD process is safe and harmless to the sea and the atmosphere environment, since it does not produce any desulfurization by-products or cause secondary pollution. In addition, the technology required in this system is simple but efficient resulting in lower investment and power consumption but yields high SO₂ removal rate (> 95%) which is higher than the conventional FGD technologies. SWFGD is generally accepted as the most simple and economical FGD choice for thermal power plant in the coastal areas.

SafBon Research

In 2007, SafBon started the key project of the National High-tech R&D Program, named “Large-sized Coal-fired Power Station Boiler Sea water-FGD Technology and Demonstration”. Through lots of research work and projects, the seawater-FGD technology for large-sized coal-fired power station boiler and its engineering design software package with self-owned intellectual property was developed.

SWFGD Process Flow Diagram

SWFGD Technical Characteristics

The main chemical reactions in the SWFGD process is shown as follows:

• SO₂ (g) ↔ SO₂ (aq)

• SO₂ (aq) + H₂O ↔ HSO₃^- + H⁺

• HSO₃^-↔ SO₃^2- + H⁺

• CO₃^2- + H⁺↔ HCO₃^-

• HCO₃^- + H⁺ ↔ CO₂ (g) + H₂O

• SO₃^2- + 1/2O₂ → SO₄^2-

With the adoption of SafBon SWFGD technology, the treated gas and discharged seawater qualities are designed as follows:

• High SO₂ Removal Efficiency: ≥ 95%
  (Outlet SO₂ Concentration: <35 mg/Nm³)
  

The treated flue gas quality:

• Dust emission ≤ 5 mg/Nm³

• SO₂ emission ≤ 35 mg/Nm³

• NO_X emission ≤ 50 mg/Nm³

Discharge Seawater quality:

• pH ≥ 6.8

• DO ≥ 3 mg/L

• SO₃^2- Oxidation Rate ≥ 90%

• Increment of COD_Mn ≤ 2.5 mg/L

SWFGD Achievement

After years of development SafBon professional team has developed excellent expertise and experience in technology R&D, system design, equipment configuration, construction, commissioning, operation and after-sales services, In the environmental protection field of large boiler seawater flue gas desulfurization, SafBon is the domestic leader in China with almost 84% market share and is targeting to be the world leader in this field soon.

This SWFGD solution has been certified as the “Ultra clean emission” solution for coal fired power plants and will be part of China’s national energy conservation and emission reduction plan.

SafBon Hazardous Waste Treatment Technology

SafBon is committed to providing safe, reliable, efficient and environmental-friendly hazardous waste treatment technology, including a full range of solutions. The "combined with rotary kiln secondary combustion chamber" incineration technology is the mainstream of hazardous waste disposal technology that mainly used in industrial waste, hazardous waste, medical waste and other solid waste incineration.

Incineration Technical features

• Wide applicability. The rotary kiln can deal with all kinds of industrial solid wastes with different properties and calorific value at the same time.

• The burning process of the mature rotary kiln. The two combustion chambers can form a good "3T" (temperature, time, agitation) burning conditions and the waste is decomposed and burnt completely.

• Two combustion chamber design temperature is between 1100°C and 1300°C, and the flue gas retention time is greater than 2 seconds which allows the dioxin to be completely broken down.

• With the process of dry de-acid and wet scrubbing, the removal rate of HCl is 99.9%, and the removal rate of SO_x is 99.3%. Dry de-acid can effectively prevent the corrosion of paste bag and metal structure.

• Bag filter with three compartment design, online and offline cleaning can be achieved.

• Lime and activated carbon supply is automatically.

• The pre-cooling section design can not only guarantee the optimum temperature of the wet air, but also helps avoid the low temperature corrosion. 

Hi-Tower Regeneration Technology

The condensate polishing system is placed between condensate pumps and low pressure feed water heaters. Hydrogen (H-OH) type deep bed polishers with high speeds are applied widely in the system. Typically, the flow rate of the polisher is 100 meters per hour.

The hi-tower separation method is employed in the external regeneration system when the amount of cross-contamination (i.e., cation resin exposed to caustic and anion resin exposed to acid during regeneration phase) must be kept to minimum. This improves the quality of treated condensate. With the high vessel separation system, the cross-contamination percentage can be minimized, it produces very low ion leakage from the resin and high quality polished condensate.

Hi-tower Regeneration System combines the resin separation tower (SPT), the cation resin regeneration, the storage tower (CRT), the anion resin regeneration tower (ART) and the other auxiliary equipment such as flush pump, roots blower, acid (alkali) storage and dosing equipment etc.

Deep Bed Condensate Polishing System

The patented hi-tower separation technology has the following features:

• Unique structure of the collector at the bottom of the mixed bed ensures resin transfer rate of more than 99.99%.

• Unique design of the regeneration device avoids flow concentration and ensures stable resin interface.

• Resin interface detector ensures high resin separation rate meaning the rate of anion resin contained in cation resin is less than 0.1% and the rate of cation resin contained in anion resin is less than 0.07%.

• High separation rate ensures long hydrogen cycle and ammonia cycle runs. Thus in order to protect the mixed bed and its resins, the pre-filters are available based on the requirements of the main equipment specifications. SafBon can also provide pleated filter elements and filter strainers.

Deep Bed Condensate Polishing System

In municipal water treatment, we have innovative and patented new technologies like precoat filtration as well classic treatment technologies and processes. SafBon has the capability to provide a full range of municipal and industrial water treatment systems according to the specific inflow water quality characteristics and output requirements.

SafBon Water Purification Technologies

SafBon uses various technology in the treatment process, including:

• Horizontal sedimentation tank;

• Turbulence flocculation sedimentation tank;

• Folded plate flocculation sedimentation tank;

• Shallow air-flotation tank;

• Horizontal flotation tank;

• Mechanical accelerated clarifier;

• Grid flocculation tank with ordinary rapid filter;

• Double valve filter,

• Variable pore filter;

• V-filter;

• Shutter filter;

• Gravity type air scouring filter;

• Precoat filter;

• High efficiency sedimentation tank;

• Integrated equipment of clarifier;

• Dissolved air flotation;

• Automatic sand filter.
  
  

Through SafBon’s expertise and experience, SafBon is able to provide the clients high-quality-low-cost water treatment systems with a combination of the most appropriate technologies.

High Efficiency Sedimentation Tank

SafBon’s purification system has been applied successfully in the Yangze River, Yellow River, other rivers and lakes, and mountainous areas, where sand content of water is higher. Moreover, SafBon adopts the advanced ultrafiltration (UF) technology to treat coal mine adit water which contains coal soil.

Lime Technology

Responding to the water reuse policy advocated by Chinese National Development and Reform Commission, SafBon has actively promoted its automated lime dosing technology. There are many tough problems in conventional lime dosing processes:

• Lime powder flying;

• Excess sludge;

• Bad waste discharging condition;
  

• Hopper rat-holing;

• Arching and bridging;

• Bad transportation condition;

• Difficulty in metering.

SafBon automated lime dosing technology, including automated powdered lime storage, metering and preparation system, solves all the problems mentioned above.

As a result, this conventional technology became a leading one. This evolved and developed lime treatment technology by SafBon is a reflection of the Chinese sustainable development strategy, in which waste is minimized and neither contaminates the environment. The lime material can be available easily and economically locally.  Considering the lower cost and excellent treatment results, the technology outperforms other chemical methods.

Powdered Chemical Feeding System

SafBon has been leading the China chemical industry, is an editor of “Automated dosing set with regards to hydrated lime milk preparation” part in China chemical industry standards. The system combines the bin activator, volumetric feeder screw and cylindrical silo, which is extensively used in the applications such as reclaimed water lime treatment, the municipal industry, the chemical industry, the food industry, the medicine industry, the coal to oil conversion industry, the metallurgy industry and the power industry.

Volumetric Feeder Screw

Track Record

SafBon has delivered more than 30 systems of reclaimed water treatment, using the automated lime dosing system for power plants, as well as more than 10 reclaimed water treatments EPC (Engineering-Procurement-Construction) projects. In addition, SafBon continues to provide wastewater desulfurized treatment systems for engineering companies.

Liquefied Natural Gas (LNG)

LNG is natural gas extracted and purified from gas fields, and then pressurized to liquefied natural gas at temperatures below -162°C.

LNG is colorless, odorless, non-toxic and non-corrosive, and is about 1/600 the volume of the same amount of gaseous natural gas. Its weight is approximate about 45% that of water.

LNG Gasification Station Process Flow Diagram

LNG/L-CNG Fueling Station 

LNG/L-CNG filling device is consisted of LNG storage tank, immersed pump, fluid adding machine, cryogenic column piston pump and skid-mounted high pressure vaporized skid, boil off gas (BOG) vaporizer, escape air gas (EAG) vaporizer, BOG buffer tank, BOG compressor, sequence control panel, storage cylinder set, gas dispenser, pipeline and valves. The station control system includes programmable logic controller (PLC) control system, gas alarm system, instrument air system and BOG collecting control system.

L-CNG Fueling Station Components

In L-CNG fueling stations, the major equipments are the LNG storage tank, LNG truck unloading system, LNG saturation heater, high pressure positive displacement pumps, high pressure LNG vaporizers, CNG storage bottle bundle/priority controls, odorant injection, dispenser and control systems.

Application

This technology has been successfully applied to the Honggang city gas project, Jiugongshan city gas project and other projects in China.

3D View of the LNG Unloading Skid

1. Local Control Panel;  2. Preset-Controller; 3. Loading Arm; 4. Mass Flow Meter

The drying process is essential in all types of sludge disposal methods. The thin film sludge dryer can be applied for municipal sludge, industrial sludge and chemical sludge drying. It can be combined with incineration, landfill and other technologies to meet the waste reduction as well as other resource requirements surrounding waste management.

Technology of Sludge Drying Combined with Power Generation

In this particular application, the sludge from municipal sewage treatment plant is converted into biofuel by drying. The dry sludge is transported to a thermal power plant for power production. Meanwhile, the heat required for drying is the waste steam from the thermal power plant. The superiority of this application lies in the full use of social resources and social division of labor to solve sludge problem. It forms a complete market-oriented and sustainable development business application.

The sludge drying combined with power generation technology includes one-stage and two sludge drying processes.

One- stage Sludge Drying Process

The process mainly includes several units:

• The sludge receive, storage and transportation unit

• The sludge drying unit

• The tail gas treatment unit

• The biological/chemical deodorant unit

• The dry sludge storage and transportation unit

• The steam unit

• The electrical, instrument and control unit

In the one-stage sludge drying process, the sludge storage and drying is operated under closed negative pressure resulting in no odor. The drying process utilizes the advanced thin film sludge dryer, and recovers the heat of waste gas as well minimizes energy consumption and costs. In addition, the process is flexible, one-stage drying process can reduce moisture content to 30~45%.

Process of One-Stage Sludge Drying Combined with Power Generation

Two - stage Sludge Drying Process

The process mainly includes several units:

• The sludge receiving, storage and feeding unit;

• The primary thin film drying unit

• The waste gas and waste heat recovery unit

• The secondary belt drying unit

• The deodorant unit

• The dry sludge storage and transportation unit

• The steam unit

The two-stage sludge drying process completely uses the waste heat obtained from the primary drying system. With the integration of energy recovery, the operational costs can be reduced. In the process, the sludge in the plasticization stage is made into particles to avoid dust generation. With this two-stage drying process, the sludge can be completely dried. The operational temperature is below 110°C, which ensures the safety of the equipment and the operators.

Process of Two-Stage Sludge Drying Combined with Power Generation

Petrochemical Sludge Drying and Incineration Technology

In this application, the petrochemical sludge drying and incineration technology uses the advanced thin film sludge dryer to realize the high efficiency heat drying of sludge and effectively improve the calorific value of sludge.

Thin film sludge dryer has an inert system, special seal structure and multiple emergency safety assurance measures can provide the system with high safety and reliability.

In view of the characteristics of oily sludge, the two section incineration system of "rotary kiln and two combustion chambers" is used for the full combustion of all the combustible materials in the sludge.

The system completely recovers the energy generated in the sludge incineration process, and uses it in thin film sludge dryer. Such an act enables the system to satisfy the vast majority of dry energy consumption. Using "dry and wet" method to treat the tail gas, tail gas standardized emissions is achieved.

Powder Coated Technology

Chinese National Development and Reform Commission (NDRC) advocates that the newly built power plants adopt air cooling units in the northern areas of China where water resources are deficient. To adhere to this policy, SafBon carried out intensive research and development of the requirements for powder coated (powdered resin) condensate polisher. 

The features of the powder coated filter includes: large operating capacity; effective removal of corrosion products from the thermodynamic system; and ferric oxide removal rates of 95% or higher.

Powder coated filter utilizes powdered resin with high regeneration rates, and this is coated on the filter element surface and can be used both for ultrafiltration (UF) and ion exchange.

We also can use this technology to treat oily condensate with powdered activated carbon demonstrating a variety of successful applications. SafBon provides: cation or anion powdered resin, fiber powder and proportionally mixed powdered resin matched with powder coated filter; special cartridge (stainless steel core and PP (polypropylene) wound yarn) with micro ratings of 5 μm, 10 μm or 20 μm.

Site View of Powder Coated Filter

The Necessities of Dual Water Supply

In Northwest China, according to water analysis report from the ministry of water resources, more than 80% well water are in class IV and V, based on Chinese surface water quality standards. Meanwhile, 90% of the water treatment plants are still using traditional water treatment methods. They can remove only a part of physical and microbial contaminations. The chemical pollutants, such as pesticide, synthetic detergent, heavy metal and other harmful substances are remaining in the treated potable water. It is seriously harmful to people’ health.

Drinking Water Purification Process

The initial water source of the drinking water is the deep groundwater in southern Guangrao County. It is transferred to Dongying water treatment plant through a 60 km-long feed pipe and the raw water will be purified in the plant.

Firstly, in activated carbon filter, the raw water will be treated by quartz sand and activated carbon, in order to reduce the turbidity and remove smell and taste remaining in raw water. Then the ultrafiltration and nanofiltration system will treat the water profoundly. An ozone system is set up for output pit, it could enhance the disinfection and oxygenation of product water. The O₃/ClO₂ disinfection complex can guarantee the continuous disinfection ability in water distribution system. With the variable frequency pressurizing system and pipe network circumfluence system, the water quality will be more stable and reliable.

The Process Flow Diagram of Central City Dual Water Supply

Dual Water Supply System

Dual water supply systems separate the safe to drink water supply and the everyday water supply, while retaining the original water pipe network. About 5% of tap water will go through in depth purification treatment again to remove organic compounds, bacteria, viruses, heavy metals and excessive hardness and other harmful substances in water, while retaining the beneficial minerals and trace elements, so as to achieve the China’s "Drinking Water Quality Standards" and is safe for consumption.

The additionally purified high-quality drinking water is sent directly to the consumers by an independent circulating high-quality pipe network, , so as to ensure the health and safety of drinking water and to meet the demand of water consumption for the various needs of the public.

Drinking Water Sites

Dual Water Supply System Feature

• High quality steel tubes                                                                                                                                        

  Pipeline direct drinking water pipes are adopted new materials with high quality. The pipe itself does not produce secondary pollution.

• Frequency conversion water supply                                                                                                                          

  Direct drinking water pipe network are all closed system, and the water supply system uses frequency conversion method, the water tank is not needed. There is no secondary pollution source.

• Recycle system                                                                                                                                                          

  Direct drinking water system adopts system circulation method, which drinking water recycles a few times every day. There is no stagnant water segment.

Characteristic of Supplied Drinking Water

• Fresh: The pure water is available at any time.

• Good taste: Removing about 90% of calcium and magnesium ions, and keeping proper hardness makes the drinking water tastes good.

• Reliability: Professional centralized management.

• Safety: Efficiency organic pollutants removal.

MBR Process

Membrane bio-reactor (MBR) is a technology which combines biological aeration and membrane separation. Through biochemical process, nitrification bacteria can convert the nitrogen into nitrite and nitrate and thus remove the ammonia nitrogen. 

The hollow fiber membrane module immersed into the reactor, usually adopts ultrafiltration (UF) membrane with pore size of 40 nm, which will mainly hold suspended solid and organic matter. Thus, the concentration of microorganisms in the reactor can be kept high and MBR can further treat secondary effluent of municipal sewage.

Membrane Bio-Reactor Process Princile

SafBon MBR

SafBon adopts the advanced immersed outside-in MBR technology, which has the following advantages:

• Removal of ammonia and refractory organic matter (ammonia removal rate approx. 92%; COD and BOD₅ removal rate >67%; effluent turbidity <0.5 NTU);

• Retaining rate of bacteria is as high as 99.999%;

• High recycle rate (recycle rate can reach 99% or higher);

• Small footprint is required, unlimited by the setting occasion;

• Easy operation and management; High level of automatic control;

• Good and stable effluent quality;

• Less excess sludge production;

• It is easy to transform from the traditional process, and it can be used as the deep treatment for the traditional process.

The SafBon MBR technology has wide application prospects in the city’s secondary sewage treatment plants and the other areas. 

Track Record & Achievements

In a unique and innovative scheme, SafBon utilizes the municipal sewage as the source of water in the Guodian Shanxi Datong second power plant, specifically in its 2×600 MW super critical unit third phase engineering phase, using the SafBon MBR + two-stage RO (reverse osmosis) system + EDI (electrode ionization) membrane technology. It is the first successful commercial scale application of this technology (16,800m³/d) in large power plant in China since 2009, satisfying all the clients need.