Design of a liquid-piston compressor for raw-wet-biogas to produce biomethane for vehicles and back up power.

Engas UK Ltd正在开发一种新型的生湿沼气压缩机，可以直接生产超高纯度的生物甲烷，用于i)为天然气车辆加油，以及ii)基于云的后备电力。该备用电源将适用于智能电网服务和离网发电。该解决方案还将出口到CNG车辆普遍且电网经常不可靠的国外。**问题：**在较小的污水处理场地、垃圾填埋气场地和许多现有的沼气厂场地，经常有大量沼气滞留，将原料沼气从一个地点转移到另一个地点将创造巨大的商机；不幸的是，由于高含水率、高水平的二氧化碳和腐蚀性的硫化氢杂质，原料沼气目前无法运输。除非沼气在压缩前干燥，否则沼气中的水分会堵塞机械活塞。在常温下，在60bar以上的压缩过程中，二氧化碳会液化，导致活塞/阀门等严重堵塞。生料沼气中的硫化氢也会导致压缩机内部的腐蚀。由于相对湿度较高，原料沼气的干燥效率很低。**解决方案：**Engas UK正在开发一种技术，将高二氧化碳含量的湿腐蚀性沼气压缩并干燥，分离出二氧化碳，从而产生200-250bar的约97%的生物甲烷，然后将其运往不同的地点使用，例如为车辆加油，或作为备用电力取代柴油发电机发电。逐步淘汰柴油备用发电机以减少当地污染的争论仍在继续，例如，德里政府已从2017年11月起禁止在德里使用柴油发电机，以减少空气污染，这为生物天然气备用发电机打开了一个巨大的市场。在250bar的生物甲烷中，体积能量密度(kWh/lt)是氢气的3倍，是最好的锂离子电池的3倍，这将是在安装GB/kW和交付GB/kWh最经济的选择下理想的储能。上述解决方案解决了**能源三难困境的所有三个方面高效率和能源安全。**该解决方案适用于现有来源的滞留沼气，也适用于在奶牛场、养猪场、新的可持续住房项目、大学校园、商业园区等将有机废物转化为生物甲烷。

"Engas UK Ltd is developing a novel raw-wet biogas compressor to directly produce ultra high purity bio-methane for i) refuelling of natural gas vehicles, and ii) Cloud-based back up power. This backup power will be suited for Smart Grid services and off-grid power generation. This solution will also be exported to abroad where CNG vehicles are common and the electricity grid is often unreliable.**Problem:** There is often a lot of stranded biogas in smaller sewage treatment sites, landfill gas sites, and many existing biogas plants sites where moving raw biogas from one location to another location will create a significant business opportunity; unfortunately shipment of raw biogas is currently NOT feasible due to the high moisture content, high level of CO2 and corrosive H2S impurities. The moisture content in biogas will block the mechanical piston unless the gas is dried upfront of compression. Then CO2 will liquefy during compression at above 60bar at ambient temperature causing serious blockage of piston/valves etc. H2S in raw biogas will also cause corrosion inside the compressor. Drying of raw biogas is inefficient due to the relative humidity causing a high level of surface water in raw biogas.**Solution:** Engas UK is developing a technology where wet-corrosive biogas having high CO2 content will be compressed and dried and the CO2 will be separated thus producing about 97% Biomethane at 200-250bar, which can be then shipped to a different location for usage e.g. refuelling of vehicles, or for power generation as back up power replacing diesel generators. There is an ongoing debate to phase out diesel backup generators to reduce local pollution and for example, the Government of Delhi has banned the use of diesel generators in Delhi from Nov 2017 to reduce the air pollution, which opens up a large market for bioCNG powered back up generators.At 250 bar biomethane has 3 times greater volumetric energy density (kWh/lt) than hydrogen, and 3 times greater energy density than the best Li-ion batteries, which will be ideal for energy storage at the most economical options for £/kW installed, and £/kWh delivered.The above solution addresses all three aspects of **energy trilemma of ""Affordable, carbon neutral, high efficiency, and energy security.** This solution would be suited for stranded biogas from existing sources and also to convert the organic waste to Biomethane at dairy farms, pig farms, new sustainable housing projects, University Campus, business parks etc."