vi.Water hyacinth Biochar

Water hyacinth Biochar, a carbonaceous solid material obtained through a pyrolysis process from solid waste materials, and has properties like extremely low thermal conductivity, high chemical stability, low flammability, ability to absorb water, and highly capture and store CO2. Recently, these properties of biochar favor its use as a partial cement replacing material in concrete construction up to 5% of cement by weight. In addition to this, every tone of biochar used in a building's envelope means that the equivalent of more or less one tone of CO2 is prevented from re-entering the atmosphere.

## **4.2 Advantages of cement replacing materials**

### *4.2.1 Environmental advantages*

The cement industry is an energy-intensive industry with energy typically accounting for about 40% of operational costs, i.e., excluding capital costs but including electricity costs. The production of cement involves the consumption of large quantities of raw materials, energy, and heat. Cement production also results in the release of a significant amount of solid waste materials and gaseous emissions. The cement manufacturing industry is under higher scrutiny these days because of the large volumes of CO2 emitted. This industrial sector is thought to represent 5–7% of the total CO2 anthropogenic emissions. Concern over the impact of anthropogenic carbon emissions on the global climate has increased in recent years due to growth in global warming awareness. In addition to the generation of CO2, the cement manufacturing process produces millions of tons of the waste product cement kiln dust each year contributing to respiratory and pollution health risks. To produce 1 ton of clinker, the typical average consumption of raw materials is 1.52 tones.

The amount of clinker needed to produce a given amount of cement can be reduced by the use of supplementary cementitious materials such as coal fly ash, slag, and natural Pozzolanas (e.g., rice husk ash, coffee husk ash, and volcanic ashes). The addition of these materials into concrete not only reduces the amount of material landfilled (in the case of industrials byproducts) but also reduces the amount of clinker required per ton of cement produced. Therefore, replacing the portion of Portland cement with those cementitious materials can substantially reduce the environmental impact of concrete associated with cement production like consumption of raw materials and energy use as well as emissions to air and avoiding environmental pollution due to avoiding as a waste.

#### a.Energy saving

The cement industry plays a significant role in global energy consumptions. Worldwide the cement industry is one of the most energy-intensive sectors in which energy represents 40% of the total production cost. The energy consumption in cement manufacturing is mainly related to the production methods that are wet methods consume more energy than dry methods. For instance, in the dry method, 1450°C of temperature is needed for the production of clinker which accounts for 97.2% of the total and the remaining is for finishing and raw materials grinding with the share of 0.9% and 1.9% respectively.
