沼氣是生物質厭氧發酵的產物,是一種高質量的可再生生物質能源,主要成分為CH4(約為55%-70%)CO2(約為30%-45%),還有少量的H2S、O2、CO、N2及其他碳氫化合物等,沼氣中的CO2降低了沼氣的能量密度和熱值,限制了沼氣的利用范圍,因此,要對沼氣進行脫碳提純以降低CO2的含量。
Biogas is the product of anaerobic fermentation of biomass and is a high-quality renewable biomass energy. Its main component is CH4 (about 55% - 70%) CO2 (about 30% - 45%), with a small amount of H2S, O2, CO, N2 and other hydrocarbons. The CO2 in the biogas reduces the energy density and calorific value of the biogas and limits the utilization range of the biogas. Therefore, the biogas should be decarburized and purified to reduce the CO2 content.
沼氣提純的技術主要有以下及方面:
Biogas purification technologies mainly include the following aspects:
1、膜分離法是近幾年發展較快的一種節能型CO2分離回收工藝,該法利用沼氣中不同組分在通過膜時的溶解度和滲透率不同,實現沼氣的分離。
1. Membrane separation method is an energy-saving CO2 separation and recovery process that has developed rapidly in recent years. This method realizes the separation of biogas by using different solubility and permeability of different components in biogas when passing through the membrane.
2、化學吸收法是利用弱堿性吸收液,在吸附塔內吸收酸性CO2,然后在高溫條件下進入解吸塔完成再生,從而達到脫除沼氣中CO2的目的。
2. Chemical absorption method is to use weak alkaline absorption solution to absorb acidic CO2 in the adsorption tower, and then enter the desorption tower under high temperature to complete regeneration, so as to achieve the goal of removing CO2 from biogas.
3、水洗法是利用CO2和CH4在水中溶解度不同,通過物理吸收,實現CO2和CH4的分離目的。
3. The water washing method is to realize the separation of CO2 and CH4 through physical absorption based on the different solubility of CO2 and CH4 in water.
4、變壓吸附法的吸附原理是利用吸附劑對CH4、CO2的吸附能力不同,對沼氣中的CO2進行選擇性吸附,使之與CH4分離。
4. The adsorption principle of PSA is to selectively adsorb CO2 in biogas to separate it from CH4 based on the different adsorption capacities of adsorbents for CH4 and CO2.
5、低溫分離法是利用CH4和CO2沸點不同,在低溫條件下將沼氣中CO2轉變為液體或固體,但CH4仍保持氣體狀態,從而實現二者的分離。
5. The low-temperature separation method uses the different boiling points of CH4 and CO2 to convert CO2 in biogas into liquid or solid under low temperature conditions, but CH4 remains in a gas state, so as to realize the separation of the two.
沼氣凈化提純技術工藝較多,開封迪爾空分有成熟的沼氣提純技術和經驗,可根據用戶能源利用目標進行設計選擇。
There are many biogas purification technologies and processes. Kaifeng Deer Air Separation Plant has mature biogas purification technologies and experience, which can be designed and selected according to users' energy utilization goals.