Sustainable Swaps for LPG Cylinders in Cooking And Heating

Bottled gas is an internationally popular energy source for cooking and heating and for barbeques. The fuel stored in the pressurised cylinder is liquefied petroleum gas (LPG).

LPG is a mixture of propane and butane which can be recovered as a condensate (referred to as natural gas liquids, or NGL) during liquefied natural gas processing. It is also produced on crude oil refineries as a light product for regional distribution in bulk, or as bottled gas.

The popularity of LPG has grown because it is perceived as a relatively clean fuel. It burns with a clean flame with minimal particulate pollution. It is also transportable to remote regions where natural gas pipelines do not run and never will. However, as a fossil fuel LPG produces carbon dioxide greenhouse gas emissions and therefore contributes to climate change.

Sustainable alternatives: a path to break through fossil energy dependence

1. Biomass gas: an innovative practice of closed-loop carbon cycle

As a green alternative to LPG, biomass gas (Bio-LPG) is triggering an energy revolution. Through anaerobic digestion technology, organic matter such as agricultural waste and kitchen waste can be converted into biogas with a methane content of more than 60%, and the calorific value can reach 90% of LPG after purification. The "National Biogas Program" implemented in India has built 5 million household biogas digesters, reducing CO₂ emissions by 1.8 million tons per year. However, please note: • Regional supply chain needs to be established for raw material collection • Insulated fermentation system needs to be equipped in low-temperature areas in winter • Sulfide purification technology affects safety of use

2. Electricity transformation: thermal energy revolution driven by clean energy

According to the International Energy Agency, as the cost of photovoltaic power has dropped by 82% in ten years, new possibilities for electricity substitution are emerging:

-The thermal efficiency of induction cookers reaches 83%, which is 40% higher than that of LPG stoves

-The heating efficiency ratio (COP) of air source heat pumps exceeds 4.0

-The use of valley electricity by heat storage electric heaters can reduce costs by 60%

Norway has achieved a penetration rate of 89% for electric cooking through the smart grid + time-of-use electricity price policy. However, the degree of decarbonization of the power grid determines the environmental benefits, and a distributed renewable energy system needs to be built in conjunction with it.

3. Direct use of solar energy: disruptive technological breakthroughs

-The third generation of solar energy technology brings changes:

-Parabolic concentrator stoves can reach a cooking temperature of 250℃

-Phase change heat storage materials enable continuous heating at night

-The photovoltaic-cogeneration system has a comprehensive efficiency of 58%

The solar-thermal hybrid system developed by Kenyan solar cooker company SunCulture has reduced rural household fuel expenditure by 70%. However, an innovative business model is needed - reducing the equipment cost from US$300 to US$0.3/day in installments.

4. Hydrogen energy substitution: early layout of future energy

Green hydrogen energy shows potential:

-Gas appliances with 20% hydrogen can directly use existing stoves

-Metal hydride hydrogen storage technology achieves safe storage at room temperature

-Methanol reforming hydrogen production device is suitable for off-grid scenarios

Japan's "ENE-FARM" project has deployed fuel cell cogeneration systems in 120,000 households, with a comprehensive energy efficiency of 95%. However, the cost of hydrogen production by electrolysis of water needs to be reduced from the current US$4-6/kg to US$2/kg to be competitive.

Transformation path and system optimization

Multi-dimensional strategies are needed to achieve energy substitution:

-Step-by-step substitution: cities promote "electricity as the main source, gas as a backup", and rural areas develop a combination of "biogas + solar energy"

-Infrastructure transformation: establish a biogas pipeline network and layout community power storage sharing stations

-Carbon pricing mechanism: impose carbon taxes on LPG and subsidize the research and development of clean alternative technologies

-User behavior guidance: develop an intelligent energy management system and achieve multi-energy complementary optimization through APP

Global energy transition monitoring shows that the implementation of alternative solutions can reduce the carbon emission intensity in the cooking field from the current 1.8kgCO₂/kg LPG to 0.3kgCO₂ equivalent. This requires the coordinated promotion of technological innovation, policy incentives and community participation, and ultimately build a new paradigm for zero-carbon thermal energy supply.