1. Raw materials and resource attributes
Natural gas:
It depends on geological resources and is obtained through the exploitation of oil and gas fields. It is a non-renewable fossil energy. Industrial applications need to rely on international imports (China's import dependence exceeds 40%), and the supply chain is vulnerable to geopolitical and market price fluctuations. For example, the Russian-Ukrainian conflict in 2022 caused the cost of industrial gas in Europe to soar.
Biogas:
It is made from organic waste (such as straw, livestock and poultry manure, and food processing waste) through anaerobic fermentation and purification. For example, a processing plant that slaughters one million pigs a year can produce about 5 million cubic meters of biogas annually, realizing "waste energy" and reducing dependence on imported energy.
2. Environmental protection and carbon emissions
Natural gas:
Although the CO₂ emitted by combustion is about 50% lower than that of coal, there is a risk of methane leakage during the mining and transportation process (the greenhouse effect of methane is 25 times that of CO₂). Industrial boilers using natural gas still need to bear the cost of carbon quotas and face long-term carbon tax pressure.
Biogas:
Waste treatment during the production process can reduce the emission of methane from landfills, and CO₂ emissions during combustion are considered "carbon neutral" (CO₂ has been absorbed during the plant growth stage). According to the "Biomass Gas Industry Outlook under Carbon Neutrality Goals", its carbon emission intensity over its entire life cycle is 70%~90% lower than that of natural gas. If used to replace coal in cement plants, the annual emission reduction of a single production line can reach 100,000 tons of CO₂ equivalent.
3. Technology and application threshold
Natural gas:
The technology is highly mature, and industrial equipment (such as gas turbines and boilers) can be directly adapted without modification. However, high-energy consumption industries (such as steel and glass) face cost pressures from "coal to gas". For example, the operating cost of a gas heating furnace is 2~3 times that of coal.
Biogas:
Although purification technologies (such as membrane separation and high-pressure water washing) are commercialized, raw material collection and pretreatment are bottlenecks. For example, straw needs to be crushed to less than 2 cm for efficient fermentation, and the cost of centralized storage accounts for 30%~40% of the total production cost. If industrial users build their own biogas projects, they need to provide supporting organic fertilizer production lines to improve economic efficiency (biogas residue can be sold as fertilizer).
4. Adaptability to industrial scenarios
Natural gas:
Suitable for scenarios that require high calorific value and stable energy supply, such as glass melting furnaces (temperatures must be above 1600°C) and chemical synthetic ammonia (hydrogen source requirements). However, high-carbon emission industries (such as power plants) face export barriers such as EU carbon tariffs.
Biogas:
More suitable for low-carbon scenarios such as synthetic biomethanol and distributed energy. For example, paper mills use black liquor biogas to generate electricity, achieving an energy self-sufficiency rate of over 60%; logistics parks are equipped with biogas filling stations, which reduces the fuel cost of heavy trucks by 30% and reduces exhaust particulate matter emissions by 90%.
